Gas leak?
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- cornwallis
- Posts: 35
- Joined: Sat Nov 28, 2015 11:12 pm
- Location: Houston, Texas
Gas leak?
After filling up my car and driving 5 miles in city traffic, I noticed a heavy gasoline smell. I noticed the outside of the tank was wet. I don’t think the tank itself has a leak but not sure what’s causing this. Appreciate any input.
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Hector
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1985 635 CSi, Auto
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1985 635 CSi, Auto
- hornhospital
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Re: Gas leak?
Probably a filler neck hose is cracked. Did you run it full as you could get it?
Ken Kanne
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann"; '95 M3 "Ashlyn"
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann"; '95 M3 "Ashlyn"
- cornwallis
- Posts: 35
- Joined: Sat Nov 28, 2015 11:12 pm
- Location: Houston, Texas
Re: Gas leak?
I filled it up full - and probably one or two more squeezes from the nozzle. I do that every time.
I imagine the gas would slosh around and wet the fill nozzle as a make turns and drive.
Is it possible to inspect the fill nozzle to look for cracks?
Is it part of the tank or a separate part?
If separate part how difficult is it to replace?
I imagine the gas would slosh around and wet the fill nozzle as a make turns and drive.
Is it possible to inspect the fill nozzle to look for cracks?
Is it part of the tank or a separate part?
If separate part how difficult is it to replace?
Hector
____________________________________________________________
1985 635 CSi, Auto
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1985 635 CSi, Auto
Re: Gas leak?
Gently ease that rubber surround up and off the filler neck. I say gently as if you are too rough you will crack the filler neck. Once it is off you will see the top of the tank, the filler neck to the tank and the breather connections - it'll be obvious where the leak is.
Edit to add; while the rubber pad is off, clean it and treat it - it will probably be pretty hard but should clean up ok.
Edit to add; while the rubber pad is off, clean it and treat it - it will probably be pretty hard but should clean up ok.
2001 Alpina B10 V8 Touring (1 of 12 rhd)
1997 Alpina B12 5.7 L (1 of 2 rhd)
1995 Alpina B10 4.6 Touring (1 of 1 rhd)
1985 BMW M635CSi (1 of 524 rhd)
1982 BMW 635CSiA (1 of 100's left from the 1000's made and still valiantly fighting against a rusty grave)
1997 Alpina B12 5.7 L (1 of 2 rhd)
1995 Alpina B10 4.6 Touring (1 of 1 rhd)
1985 BMW M635CSi (1 of 524 rhd)
1982 BMW 635CSiA (1 of 100's left from the 1000's made and still valiantly fighting against a rusty grave)
- cornwallis
- Posts: 35
- Joined: Sat Nov 28, 2015 11:12 pm
- Location: Houston, Texas
Re: Gas leak?
Hi sharkfan, thanks for the advice. Busy week but I’ll check this out during the weekend. From the schematic below, looks to be one of the rubber seals (#2 or #3) could be bad. I’ll check in later. I hope it’s not weld/joint between the filler neck and tank.
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Hector
____________________________________________________________
1985 635 CSi, Auto
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1985 635 CSi, Auto
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Re: Gas leak?
Hector, number 3 is "possible" (gas cap gasket) but I would be taking a closer look at the 3X vent tubes adjacent to the filler neck, which I would also check, for corrosion, etc.
You will be able to see a lot more once you carefully remove item number 2
You will be able to see a lot more once you carefully remove item number 2
Bobbo
1980 633 CSi Cypress Green/Pearl Beige
2017 X5 M Sport Xdrive 35i Carbon Black/Ivory White
2005 330 Ci ZHP Cabrio Imola Red/Bone/Black
- cornwallis
- Posts: 35
- Joined: Sat Nov 28, 2015 11:12 pm
- Location: Houston, Texas
Re: Gas leak?
Thanks Bobbo, I’ll check that out too. Hope it’s not the vent tubes.
Hector
____________________________________________________________
1985 635 CSi, Auto
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1985 635 CSi, Auto
- cornwallis
- Posts: 35
- Joined: Sat Nov 28, 2015 11:12 pm
- Location: Houston, Texas
Re: Gas leak?
After removing the rubber cover (#2 above) degreasing and cleaning the area where it connects to the tank, I didn’t see any obvious issues: no corrosion at the vents tubes . I did tighten the hose clamps on the vent hoses and the gas cap gasket likely needs replacement. Hope this fixes it.
Question — the vent hoses are braided and look frayed— possible this is where gas was seeping. Where do these lines end up? Considering replacing these. Thanks!
Question — the vent hoses are braided and look frayed— possible this is where gas was seeping. Where do these lines end up? Considering replacing these. Thanks!
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Hector
____________________________________________________________
1985 635 CSi, Auto
____________________________________________________________
1985 635 CSi, Auto
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- Platinum Member
- Posts: 3726
- Joined: Thu Apr 08, 2004 3:24 pm
- Location: Gilroy (SF Bay Area) CA
Re: Gas leak?
They go to a sort of "vapor reservoir" in the trunk, behind the right hand side inner panel
They don't appear to be in bad condition, however
I would at least tighten the clamps, for starters, and I would not top off when filling up either
They don't appear to be in bad condition, however
I would at least tighten the clamps, for starters, and I would not top off when filling up either
Bobbo
1980 633 CSi Cypress Green/Pearl Beige
2017 X5 M Sport Xdrive 35i Carbon Black/Ivory White
2005 330 Ci ZHP Cabrio Imola Red/Bone/Black
- 86_6series
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Re: Gas leak?
Look like the gas cap gasket will solve your problem.
The wet fuel is running down the 3 hoses thru the
grommets from the gas cap cavity area and spilling
onto the gas tank cover.
The wet fuel is running down the 3 hoses thru the
grommets from the gas cap cavity area and spilling
onto the gas tank cover.
86-635CSi
96-MB C220 SOLD
98-740i
71-Continental MK3
96-MB C220 SOLD
98-740i
71-Continental MK3
Re: Gas leak?
Those fabric covered hoses that BMW used WILL fail. I have replaced the fuel lines in both my 6ers and my BMW motorcycles produced during the same era because they will seep gas. They will appear to be "wet".
This is a very common problem, and I have even encountered some who have sold their cars because of the fuel smell they could not find. Usually filling the tank makes this problem worse.
Replace one line at a time, and use new worm drive clamps. If memory serves, there are four separate fuel lines to renew between the filler neck and expansion tank under the rear parcel shelf.
This is a very common problem, and I have even encountered some who have sold their cars because of the fuel smell they could not find. Usually filling the tank makes this problem worse.
Replace one line at a time, and use new worm drive clamps. If memory serves, there are four separate fuel lines to renew between the filler neck and expansion tank under the rear parcel shelf.
'86 635CSi 5-sp
'88 M6 Canadian
'03 530i 5-sp - ordered new, now gone, victim of someone else's spin-out on I880
'02 530i 5-sp - now my daily driver - finally replaced my original 530i
'96 Ford F-150, 5-sp too
'88 M6 Canadian
'03 530i 5-sp - ordered new, now gone, victim of someone else's spin-out on I880
'02 530i 5-sp - now my daily driver - finally replaced my original 530i
'96 Ford F-150, 5-sp too